内容标题35

　　Compared with traditional motors, what are the advantages of variable frequency motors?

　　·More energy saving

　　All household appliances produce harmonic voltages and currents of varying degrees in the operation of the motor, enabling the motor to operate under non sinusoidal voltage and current. The higher harmonics will cause the increase of copper consumption, rotor copper consumption, iron loss and additional loss of the motor stator, and the most notable is the copper consumption of the rotor. Because the common AC asynchronous motor rotates at the synchronous speed corresponding to the frequency of the fundamental wave, the high harmonic voltage can produce a large rotor loss after cutting the rotor guide with a larger difference. In addition, additional copper consumption due to skin effect should also be considered. These losses will make the motor extra heat, reduce efficiency and reduce output power, but if using variable frequency motor, its energy consumption can be reduced by about 20%-30%.

　　·Long service life

　　The carrier frequency of the motor is about several thousand to ten thousand kHz, which makes the stator winding of the motor bear a high rising rate of voltage, which is equivalent to the high steepness of the motor, so that the interturn insulation of the motor is more severe. The variable frequency motor can work under the voltage of rectification and filter, the performance can be more stable, and the life is longer.

　　·Small noise

The vibration and noise caused by electromagnetic induction, mechanical ventilation and other factors become more complex. Each time harmonic contained in the variable frequency power supply is interfered with the inherent space harmonics of the electromagnetic part of the motor to form various electromagnetic exciting forces. When the frequency of the electromagnetic force wave is consistent with or close to the natural vibration frequency of the motor body, a resonance phenomenon will occur, thus increasing the noise. Due to the wide operating frequency range and large speed range, the frequency of various electromagnetic waves can hardly avoid the natural vibration frequency of each component of the motor. But inverter motor can solve these problems effectively.